Effects Of Cotton Straw Incorporation On Soil Microbial Biomass Carbon,Nitrogen, Phosphorus And Soil Dissolved Organic Carbon Of Continuous Cropping Cotton Field

Xinjiang is China’s major cotton production base,due to the lack of water resources in Xinjiang and constrained by natural conditions, leading to serious on cotton production even as phenomenon.The objective of the experiment is to study the effect of straw incorporation on soil nutrients;soil microbial biomass carbon,nitrogen,phosphorus and soil dissolved organic carbon content in the continuous cropping cotton field,for evaluation of straw returned to the influence of long-term continuous cropping soil quality and fertility of cotton fields to provide scientific theoretical basis. Results showed that:1. Cotton straw incorporation and no cotton straw incorporation all could increase the soil nutrients content significantly in three soil depth. Besides, with the time of continuous cropping increasing, soil nutrients content was remarkably raised,This continued high fertilizer inputs on production-related.Straw for long-term continuous cropping Cotton Soil nutrient accumulation has significant role in promoting.With the increase of straw and continuous cropping,straw effect on the accumulation of soil nutrients significantly increased.Compared to the long-term continuous cropping without straw to field,soil nutrient content of the Cotton straw incorporation significantly increased than no cotton straw incorporation.Besides,with the extension of continuous cropping, the growth rate increased significantly,in the straw for 30 years, and even when the soil nutrient content reaches a maximum.Results showed that straw incorporation can reduce the amount of fertilizer inputs on production agriculture to a certain extent,conducive to the improvement of soil quality and it is beneficial to improve soil fertility.2. Cotton straw incorporation could all increase the SMBC, SMBN, SMBP content significantly in three soil depth.Besides, with the time of continuous cropping increasing, the SMBC, SMBN, SMBP content was remarkably raised. in the0~20cm soil layer, compared with the 5, 10, 15, 20, 25 years continuous cropping, the SMBC content in 30 years increased by116.59%, 86.24%, 101.58%, 28.86%, 7.99%, the SMBN increased by 114.0 8%,82.08%, 99.65%, 27.84%, 7.15% and the SMBP increased by 65.69%, 6. 93%, 34.21%, 1.42%, 2.22%.The straw removal treatments, the SMBC,SMBN,SMBP was remarkably declined with the time of continuous cropping increasing. Results showed that cotton straw incorporation can increase the soil microbial biomass carbon, nitrogen, phosphorus content in the long-term continuous cropping cotton field,and alleviate the negative impact of cotton continuous cropping, so that it is beneficial to improve soil quality and soil fertility.3.Cotton straw incorporation could all increase the soil organic carbon content significantly,besides, with the time of continuous cropping increasing, the soil organic carbon content was remarkably raised.The straw removal treatments, with the time of continuous cropping increasing, the soil organic carbon content was remarkably decrease.Results showed that,cotton straw incorporation could effectively improve soil organic matter content,and it is important to improve soil texture.